1921.] Dore.—Malarial Infection in the Imported Skylark. 
127 
Measurements of hosts, erythrocytes :— 
Average 
Average 
Length. 
Breadth. 
Corpuscles 
.. 11-2 /x 
6-2 /x 
Nuclei 
.. 4*9 /x 
2-7/x 
Measurements of erythrocytes containing parasites 
Average 
Average 
Length. 
Breadth. 
Corpuscles 
.. 11-3/x 
7-6 /x 
Nuclei 
. . 4-8 /x 
2*8 /x 
Description of Six Successive Parasites .—(1.) Spherical in form ; mea¬ 
sures 4*8 /x in diameter ; protoplasm deep blue, showing slight vacuolation ; 
nucleus appears as a broad deeply staining band extending across the 
parasite ; one large mass of melanin towards one end, three granules of 
melanin lying at side of nucleus. 
(2.) Spherical in form ; measures 6-4 /x in diameter ; protoplasm deep 
blue; nucleus stained faintly, spherical, situated at edge of parasite; 
sixteen granules of melanin opposite nucleus. 
(3.) Spherical in form ; measures 3-2 /x in diameter ; protoplasm pale 
blue, showing slight vacuolation ; nucleus stained deeply and occupied one- 
third of the parasite ; melanin absent. 
(4.) Oval in form ; measures 4*8 /x by 3-2 /x ; protoplasm pale blue, 
showing marked vacuolation ; nucleus stained deeply, central in position ; 
one small compact mass of melanin at each end. 
(5.) Oval in form; measures 8/x by 6-4 /x ; protoplasm pale blue ; 
nucleus stained faintly and showing slight vacuolation, central in position ; 
seventeen granules of melanin scattered. 
(6.) Spherical in form; measures 1-6/x in diameter; protoplasm pale 
blue, large vacuole in centre ; nucleus stained deeply, spherical and situated 
towards one end ; melanin absent. 
Halteridium (Danilewskyi) of the Skylark ( Alauda arvensis). 
The infected birds were either shot or captured at Kimihia, in the Wai¬ 
kato district, during January, 1921. Blood-films were prepared from the 
heart, fixed in absolute alcohol, and stained by the Giemsa method. The 
number of infected birds from this district totals approximately 3 per cent. 
In the case of adult birds the infection was usually slight, and sometimes 
a prolonged examination revealed fewer than twelve parasites on a slide. 
The most heavily infected adult bird showed halteridia in 8 per cent, of its 
erythrocytes. Infection was more severe in the younger birds, especially 
nestlings, often as many as 14 per cent, of their erythrocytes being invaded. 
Examinations for the piesence of ecto-parasites on these birds were negative. 
The halteridia were similar in appearance to those observed in the im¬ 
ported song-thrush (TUrdus musicus )* but slightly larger, measuring 10-2 /x 
in length by 2-2 /x to 3-6 /x in breadth. 
Measurements of erythrocytes infected with adult parasites :— 
Average Average 
Length. Breadth. 
Corpuscles .. .. .. .. 11-6/x 6-8/x 
Nuclei .. .. .. .. 4-8/x 3-2 /x 
* A. B. Dore, Notes on some Avian Haematozoa observed in New Zealand, 
N.Z. Journ. Sci. & Tech., vol. 3, pp. 10-12, 1920. 
